Screw cap



Jm 14, '1947.` C. J'. sALvQ 2,414,395

SCREW CAP Filed Jan. 3,' 1944 FIG. I.

N YTY meme Jui. 14. 1941 2,414,395 or-'Flcs scaaw car y Charles J. Salvo, Somerville, Mass., assigner to United-Rexall Dru Delaware l CNhPllly, a corporation of Application January 3, 1944, Serial No. 516,809

This invention relates to caps, and with regard to certain more specific features to screw caps for containers such as Jars, bottles and the like. The invention relates also `Ito their method of manufacture.

Among the several objects of .the invention may `be noted the provision of a screw cap made primarily of easily obtainable materials such as cardboard, iibreboard, or the like, which will have a strength and rigidity comparing favorably with that of a metal cap; the provision of a cap of this class wherein the problem of economically incorporating a strong metal thread is successfully met; and the provision of a cap of the class described which lends itself lto economical, quantity manufacture. Other objects will be in part obvious and in'part pointed out hereinafter.

The invention accordingly comprises the steps and sequenceof steps, elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified inthe structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

view pf a threadforming 111g;

Fig. 4 is a cross section of the Fig. 2 blank after a forming operation and after insertion of a sealing disc, the dotted lines indicating the preliminary formative step of Fig. 2;

Fig. 5 is an enlarged corner detail section of the cap:

Fig. 6 is a plan view of an alternative form of lug-supporting band; and,

Fig. 7v is an enlarged detail of an alternative foi-m of cap employing said band of Fis. 6.

Similar reference characters indicate corre- 6 Claims. (Cl. 215-43) distances on adjacent tabs. The tabs are equally spaced, as indicated, and the radial distances from the center of the blank to the slits increases by equal increments between successive tabs. The

, result is an equi-angular spiral of slits (Fig. 2).

I Thus, when the tabs 'I are turned up at right angles to the central portion of the blank so as to close the notches l and form an inner annular layer or cylindric skirt, the slits I3 take up positions on a helical locus within said cylindric; skirt (Fig. 4). The tabs 'l are preferably not turned up until thread-forming lugs II are inserted into the slits I3, as indicated by the dotted lines in Figs. 2 and 4.

pads I9 and 2I.- One pad I9 is preferably longerV than the other pad 2 I. The total thickness oi the layers forming the ange I1 is only slightly sponding parts throughout the several views of the drawing.

Referring now more particularly to Fig. l, there is shown for example at numeral I a glass jar having a molded male thread 3 with which the female thread of the cap is to cooperate.

F18. 2-shows a flat circular blank l which forms Athe main body of the cap. This is provided with radially extending tabs 1 between which are relieving notches 9. `The tabs 'I lieoutside of a circular score line II. The blank is composed of cardboard, nbreboard or the like. The central like.

greater than the width of the slit I3. The lateral length of each ange I'I is about equal to that of a slit I3. Thus the lugs I5 may be applied to the blank 5 by inserting the flanges i1 through the slits I3 wherein they are frictionally heid. The pads I9, and 2| are then located beneath the tabs 1 prior to turningsaid .tabs up into their'cylindric relationship. Insertion oi the lugs is quite simple to perform en masse by circularly relatingthem in a suitable jig or ilxture as required by the locations of the slits I3 in the blank, and then forcing the blank down over the positioned lugs so that the slits are forced over the anges I 1. Other means for inserting the lugs may, of course, be used.

The purpose of making thecoplanar pads I9 and 2l of unequal lengths is so that they may be positioned, in the case of the outermost slits I3 to prevent extension of the lugs beyond the tabs,

andV in the case of the innermost slits I3 .to prevent extensions of the lugs within the score line II. To accomplish this it is only necessary to invert the radial relationship of the pads `I9 and 2| as indicated at the left and right respectively at Fig. 2.

After the lugs have been inserted as indicated by the dotted lines of Fig. 4,` the lug-bearing tabs 'I may be turned into the cylindric position shown by the use of a. suitable bending die or the It is preferable that before turning up the tabs i a sealing disc 23 be applied to the blank so that it becomes located within the discontim uous helical thread formed by the lug flanges I1.

Next. in order to hold the tabs 1 in the @yundrie relationship shown, there is slipped over the outside of the tabs 'I and the exterior of the pads I9 and 2i a cardboard or similar ring indicated at numeral 25 and forming an outer annular layer. 'I'his ring may be made up in various ways but la preferable one is to cut it from a pre- Each lug I5 comprises a deformable preferably The result is a strong and rigid cap'oit neat appearance wherein only a very small amount ofy metal is used. It will be understood that if desired the lugs i may be made of fibre, plastic or other suitable material. The discontinuous character of the thread is not detrimental to proper cooperation withy the male thread 3 on the lar and at, the Sametime it saves material that would be otherwise used to make the thread continuous.

It is to be understood that the ring 25 snugly fits the outside of the members which it encircles so as to resist any expansive strain. 'l'hus also.

tilt of 'pads lil and 2i is resisted, ii desired ring 25 maybe wrapped on (in situ), rather than being pre-wound.

An advantage of forming the lugs as indicated with the double-layered ilange il and the smooth, rounded .edges I8, is that said edges form a desirable type of engagement `at the root of the thread 3. p

In Fig. 6 is shown. a modification in which a cardboard, bre or like strip 3l is provided in its dat condition with slits 39, arranged on a bias but individually parallel to the length of the strip. Into these slits 39 are inserted the lugs l5 f as indicated, the lugs beingreversed at a suitable central point on the strip to avoid extension of any pad IgorI 2l from a lateral edge of the strip.

The strip 37 is then wound into a cylinder or band'wlth the extending ilanges il directed in-l' ward to form the desired discontinuous thread. This thread-bearing ring is then inserted into the flanged portion 4l of an ordinary drawn or like cap 43 and forms an inner annular layer therein.

A. drawn cap vis for example made simply by pushing thecentral portion of a circular blank through a drawing die so as to form a skirt oi' its edge portion. The skirt is part di in Fig. l and forms an'outer annular layer. Adhesive 32 is used between parts di and Si thus anchoring them and the lugs Id. It nis to be understood that before inserting into drawn cap Iii, 43 the thread-bearing ring (formed of the lug-bearing strip 3l), a suitable sealing disc d5 is inserted. An exterior band i1 is then applied as above-- described in connection with the band 25.4 This band il is also provided with a suitable decorative cover e9 if desired and on'the top of the cap is another suitable cover di. Unlike the cover 3i, the cover HS is not laid over beneath the cover 5l on top of cap d3. 'This is optional;

In view of theabove, it will be seen that the several objects oi the invention are achieved and other advantageous results attained.

As nmany changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description 'or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense. l claim:

` 1. A cap comprising a ymember formed inte-A grally of a circular part and 'axially directed tabs. slits in the respective tabs successively po sitioned at increasing distances fromA the circular part, lugs cooperating with the slits, each lug` comprising a crimped strip. forming a doublelayered ilange extending through a slit, the remainder of each lug forming `coplanarfllsds .engaging the outside of a tab, and va constraining band formed around said tabs and engaging all of said pads.

l2. A cap comprising a member formed integrally of a circular part and axially directed tabs cooperating circularly to vform a. skirt, slits in the respective tabs successively positioned at increasing distances from the circular part,J lusscooperating with the slits, each lug comprising a,

crimped "strip forming a double-layered iiange extending through a slit and forming co-planar pads of unequal lengths engageable with the out. f side of the skirt, the relationship of the of unequal pads of some lugs being reversedwlth respect'. to those of others, and a band formed around said skirt and engaging all of said pads..

3. A screw cap comprising a drawn cup having a cylindrical skirt, a holding band outside of and engaging said skirt, a lug-holding strip formed cylindrically -inside of said skirt, said strip having openings formed on a path which is at `a bias to the length of said strip, and lugs `having extensions directed radially inwardly. through said openingsyand holding portions loy cated between and engaged by the strip and the skirt, said extensions fitting tightly in said openings to `prevent shifting movements of saidlugs, said skirt preventing radialand tilting movements of said lugs. e j 'i 4. A screw cap comprising acup-shaped member including a cylindric part having an outside wall surface and spaced slits through said cylindrie part, the slits lying substantially along a helical path on said cylindric part, lugs having iiat ange portions extending through the slits g and pad portions lying on said outside wall sure face, and enclosing banding means'attached to the outside wall surface of said cylindric part and f engaging said lugs to anchor them against radial and tilting movements.

5; A screw cap comprising a cup-shaped member having a, cylindrical wall, said wall includ ing an inner annular layer having a plurality of slits therein spaced substantiallyalong a helical path, lugs having hairpin-shaped portions ex-` tending through said slits and oppositely directed coplanar pad portions engaging the outer periphery of saidinner annular layer, said cylindrical wall including an outer annularlayer surrounding said inner annular layer and engaging said pad portions and conning said lugs in said slits to prevent radial and tilting movements thereof, said hairpin-shaped portions tting tightly in said slits to prevent shifting movementsthereof. i

6. A screw cap comprising a drawn cup having a cylindric skirt, a holding band surrounding and engaging said skirt, a lug-holding strip formed cylindrically inside said skirt, said strip having slits therein on a path which is at a bias to the length of said strip, and lugs having extensions directed'radialiy inward through said slits and holding portions located between and engaged Y by said strip and said skirt, each lug having a crimped portion forming the said extension, vsaid crimped portion comprising a double-layered flange having a rounded end, `the remainder of each` lug comprising coplanar pads forming said holding portions. l

CHARLES J. SALVO. 

